642 BRITISH ORIBATIDiB. 



thick, almost conical, projecting slightly beyond the 

 rostrum, but hidden by the rostral hairs from the 

 dorsal aspect ; the terminal joint is densely haired, and 

 has one or two very long hairs. The mandible (fig. 16) 

 is small but very remarkable ; the fixed arm of the 

 chela is shorter than the movable arm, and is narrowed 

 to a sort of neck before joining the body of the 

 mandible ; it has four large teeth ; above and close to it 

 is a projection from the body of the mandible, which 

 is rather like a larger copy of the fixed chela, but is 

 more hand-like in form, and cut into five very deep 

 teeth or spikes ; above this is the ordinary hair or 

 spine. The movable arm of the chela is long and 

 thin, but does not depart greatly from the usual type. 

 The apodemata are joined to the sternum. 



Legs rather short, hind pair not reaching the 

 posterior margin ; gradually diminished in thickness 

 from the proximal to the distal ends. There are long 

 tactile hairs on the first tibiae ; a whorl of short, curved, 

 rather woolly spines on each of the three central 

 joints of each leg, and the usual fine hairs on the tarsi. 

 Claws monodactyle, long, very little curved. 



Abdomen somewhat pyriform, slightly truncated 

 anteriorly ; moderately arched. The whole notogaster 

 is strongly and coarsely reticulated, reticulations about 

 120 to the millimetre ; the ridges of the reticulations 

 not above a sixth of the width of the depressions 

 between them. The abdomen is distinctly divided 

 into four segments ; the segments are capable of slight 

 telescopic retraction and extension. On each segment 

 is a row of large, colourless, serrated spines, which 

 usually lie flat on the notogaster, hut can he erected, 

 apparently at the will of the animal ; all the spines are 

 erected together, never separately ; the erection would 

 seem to be due to the movement of the segments. 

 The spines on the second segment are the shortest, 

 and those on the third the longest. Kound the 

 posterior margin are about eight short, curved, woolly 

 hairs, like those on the cephalo thorax. The genital 



